The present invention relates to the diagnostic imaging arts. It finds particular application in conjunction with diagnostic imaging in MRI scanners for oncology treatment applications and will be described with particular reference thereto. It will be appreciated, however, that the invention is also applicable to other types of diagnostic oncological imaging and for other diagnostic imaging for other purposes.
In oncological planning, the oncologist typically generates a plurality of x-ray, projection images of a region to be treated. The images show bone and other internal structures, but do not necessarily differentiate the tumor from non-cancerous tissue. However, from an apriori knowledge of anatomy and the nature of the carcinoma, the oncologist estimates the center of the tumor and its size (diameter).
One of the priorities in oncological procedures is accurately aligning a high power tumor killing x-ray beam with the internal tumor. If the selected trajectory is even slightly off, the x-ray beam will treat most of the tumor, but leave a small segment un-irradiated and damage healthy tissue. Un-irradiated tumor tissue can survive the treatment.
The oncologist determines a plurality of trajectories through the tumor which miss neighboring radiation sensitive tissue or radiation attenuating bone. Once the trajectories and points of entry into the patient have been determined, the oncologist positions a linear accelerator (linac) to aim its high energy x-ray beam to enter the patient at the selected point of entry and follow a selected trajectory. Optionally, after the linac is aimed, the operator opens the collimator and reduces the energy of the beam. An x-ray detector is positioned to receive the beam and generate a projection image of the irradiated region. If this shadowgram shows proper alignment, the beam is narrowed and its energy increased for treatment. Ideally, the x-ray beam is collimated to have a diameter slightly larger than the tumor to be irradiated. Making the diameter of the beam too large is detrimental in that it irradiates and harms healthy tissue. Making the beam diameter smaller increases a probability that cancerous tissue goes unirradiated. The more precisely the size, shape, and position of the tumor are known, the narrower the treatment beam can be collimated to minimize the irradiation of surrounding tissue while assuring the irradiation of all cancerous tissue. Because the oncologist is estimating the size and location of the tumor without precise visual confirmation, the treatment beam is typically wider than necessary to assure all cancerous tissue is irradiated.
Typically, the treatment process is repeated through a plurality of different trajectories to maximize the radiation at the tumor while minimizing radiation through surrounding tissue.
The present invention provides a new and improved method and apparatus which overcomes the above-referenced problems and others.
In accordance with one aspect of the present invention, a diagnostic imaging system is given. A magnetic resonance scanner generates an image of a portion of a patient including a medical malignancy. An operator inputs requests using a user interface having controls of a typical oncology linac. A coordinate conversion algorithm converts the input from the user interface into a form that can be utilized by the magnetic resonance scanner. A video processor withdraws selected portions of the image and converts them into a form suitable for a human readable display.
In accordance with another aspect of the present invention, a method of diagnostic imaging is given. Oncology linac controls are used to indicate a candidate treatment route through a patient. Control signals from the linac controls are converted in control signals for a magnetic resonance apparatus. A projection image along the treatment route is generated and displayed.
In accordance with another aspect of the present invention, an oncological treatment system is given. A high voltage linac is used to irradiate a malignancy in a patient, and a magnetic resonance apparatus is used for planning a procedure.
In accordance with another aspect of the present invention, an MRI hardware upgrade is given. A control panel with controls similar to those of a linear accelerator used for oncology purposes is translated by a conversion algorithm from a gantry, table, collimator coordinate system to a conventional MR slice center, orientation coordinate system.
One advantage of the present invention resides in its improved differentiation of soft tissue.
Another advantage of the present invention is that it facilitates a reduction in radiation doses in oncological treatments.
Another advantage of the present invention is that it facilitates location of internal patient structures from the exterior of the patient based on diagnostic images.
Another advantage of the present invention is that it reduces total patient radiation dose relative to x-ray and CT diagnostic imaging techniques.
Another advantage resides in the ability to control slice thickness and depth.
Still further benefits and advantages of the present invention will become apparent to those skilled in the art upon a reading and understanding of the preferred embodiments.